Along with increased health consciousness among consumers in recent years, the desire for vegetable drinks which can be easily consumed is growing.
However, presently available vegetable drinks are a mixed tomato juice made from about 90% tomato and about 10% other vegetables, a mixed juice made from vegetables which are comparatively odorless, such as carrot and spinach, and a major portion of fruit juice, and the like. With the exception of tomato juice and carrot juice, there are no vegetable juices which are true vegetable juices commercially available at the present time.
When a juice extracted from some vegetables belonging to the Brassica family, such as cabbage, broccoli, Brussels sprouts, cauliflower, and kohlrabi, which are reported to exhibit the capability of preventing cancerous growth, or other vegetables, such as radish, onion, or egg plant, is provided as a drink, as is, or mixed with a fruit juice, this juice produces a distinct odor when stored at room temperature. Such a juice cannot be used as a raw material for manufacturing canned juice or products aseptically filled in paper receptacles to be distributed at room temperatures.
The inventors of the present invention have previously found that a vegetable juice at close to a neutral pH with no objectionable vegetable or other unusual odor can be produced by adding an edible acid such as an organic acid to vegetable juice and treating this juice with an weakly basic anion exchange resin by a batch method or circulating the juice through a column packed with a weakly basic anion exchange resin. The inventors found that the resulting juice is suitable as a raw material for producing drinks which can be stored at high temperatures. The inventors then filed a patent application (Japanese Patent Application Laid-open No. 79351/1995).
However, because the weakly basic anion exchange resin used in this method contains amine as an active group, the treatment of vegetable juice with this resin easily causes imperfect binding sites of the amine to be exposed and to shift into the recovered fluid, leaving an unpleasant odor which is called an objectionable resin odor.
Although it is possible to kill this unpleasant odor to "a degree that this resin odor is not specifically noticed" by diluting the treated vegetable juice to produce a drink with a vegetable juice concentration of about 10-20%, by mixing the vegetable juice with a fruit juice, or by adding a perfume possessing an aroma which exceeds this objectionable resin odor, incorporation of an amine compound in food is not desirable from the viewpoint of food hygiene. Improvements in this method are therefore desired.
Accordingly, the development of a process for preparing vegetable juice without an amine odor due to a weakly basic anion exchange resin while utilizing the superior odor removal action of this resin has been desired. An object of the present invention is to provide a vegetable juice overcoming the problems in conventional vegetable juices.